Electronic audible signalling devices

ABSTRACT

Electronic audible signal devices such as doorbells, buzzers, beepers, telephone bells, school bells, bicycle bells, sirens, signaling bells in general and signalling devices in general are provided by novel combinations of random voltage generators, voltage controlled tone generators, pulsers, triggers, pulse shapers, keyers, audio generators, delay devices, amplifiers and loudspeakers.

United States Patent [72] Inventor Raymond Scott 3,284,796 I 1/1966Borsattino et al 340/384 3 Willow Park Center, Huntington, N.Y.3,346,857 10/1967 Cromer, Jr. 340/384 X [21] P 742'! PrimaryExaminer-John W. Caldwell {22] Filed June 7. 1968 A E h Isl b k PatentedJune 22' ssrstant xammer 1c ae o as y Attorney-Alfred W. Barber [34]ELECTRONIC AUDIBLE SIGNALLING DEVICES 6 Claims, 9 Drawing Figs.

[ Cl 340/384 ABSTRACT: Electronic audible signal devices such as door-[Sl] lnt.Cl G08b 3/00 b ll buzzers, beeper-s, telephone bells, schoolbells, bicycle 0t E bells sirens ignaling in genera] and ignallingdevices in general are provided by novel combinations of random volt-[56] References Cmd age generators, voltage controlled tone generators,pulsers, UNITED STATES PATENTS triggers, pulse shapers, keyers, audiogenerators, delay 3,254,336 5/l966 Campbell 340/384 devices, amplifiersand loudspeakers.

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RAYMOND SCOTT ATTORNEY PATENTEU JUN22 |97l SHEET 2 0F 5 INVENTOR.

RAYMOND SCQTT ATTOR N EY PATENTEflJIIIIzzIsII 3587-094 SHEEI 3 BF 5 1;73 FEEDBACK 7 7 G2 66 )8 o 2 TRIGGER To E 67 AUDIO N cIRcuIT GENERATORKEYER AMPLIFIER 64 PUSH PULSE BUTTON SHAPER FIG 3 8| 83 PULSE SHAPER fieAuoIo GENERATOR KEYER 3 95 MULTI- AUDIO V'BRATOR AMPLIFIER 90 94 AUDIOGENERATOR KEYER 92 ,GO L

PULSE sI-IAPER I ,1? 82 FIG 4 76 PUSH INVENTOR.

BUTTON RAYMOND scOTT BY ATTORNEY ELECTRONIC AUDIBILE SIGNAILLING DEVICESBACKGROUND OF THE INVENTION 1. Field of the Invention Class340Communications, Electrical and subclass 393audible, combined orplural (e.g. manual and electrical, bell and buzzer).

2. Description of Prior Art Prior art devices have includedelectromechanical bells generally including a metal bell stroked by anelectrically driven clapper. Such bells have been programmed as by meansof a punched tape or similar means for initiating or programming thestroking of the bell.

When considered in the light of the concepts in accordance with thepresent inventions, these prior art electromechanical devices arerelatively inflexible and limited in performance. The mechanical bell,for example, emits only one tone so that for a wide range of tones alarge number of bells would be required. There are many otherlimitations as well, such as the mechanical clapper, which has a naturalperiod limiting the rate at which the bell may be struck. The volume isalso an inherent characteristic of the bell which can be changed onlyslightly as by stroking more or less vigorously.

SUMMARY The present invention comprises a completely electronic bellsystem except for the initiation pushbutton and the loudspeaker outputtransducer. The clapper is simulated by pulsers and triggers; the belltone and characteristic by tone generators and pulse shapers; and theacoustical output by loudspeaker transducers. However, the electronicbells and buzzers in accordance with the present invention are far moreflexible and versatile than the former electromechanical devices. Thecharacteristics which were inherent in the rigid bell are not onlywidely variable but are under complete electronic control or arecompletely random as the operator or user chooses. Mechanicallimitations of speed tone, loudness, pitch and other characteristics arecompletely eliminated and overcome in accordance with the presentinvention. Thus, new concepts applications and capabilities areprovided, many not considered previously.

A wide range of signaling devices are provided with tone, pitch, attack,decay and other characteristics variable in practically unlimitedvariety. The extent of variation and character of various signalingdevices in accordance with the present invention will be clearlyunderstood from the detailed description of the invention given below inconnection with the various figures of the drawing.

In the Drawing:

FIG. 1 is a block diagram of one form of the present invention.

FIG. 2 is a detailed schematic circuit diagram of the form of theinvention shown in FIG. I.

FIG. 3 is a block diagram of a modified form of the present invention.

FIG. 4 is a block diagram of another form of the present invention.

FIG. 5 is a block diagram of still another form of the presentinvention.

FIG. 6 is a block diagram of a modified form of a portion of the form ofthe invention shown in FIG. 5.

FIGS. 7, 8 and 9 are still further modified forms of a portion of theform of the invention shown in FIG. 5.

FIG. 1 is a block diagram of one form of the present invention.Operation of the device is initiated by closing a switch such asmomentary contact pushbutton 113 is connected to trigger monostableswitch 114 which applies, for a predetermined period of time (dependingon the constants of the monostable switch), energizing voltage to thesystem rendering all of the other blocks operative for this period oftime. When the system has thus been energized, the sequence ofoperations described below is started.

FIG. ll then operates with a voltage controlled oscillator I0 producinga tone which is applied to keyer 8 over line 9. Pulser 4 rate controlledby a suitable rate control device 5 connected over line 6 turns keyer 8on and off over line 7. Meyer 8 in going on passes tone signals fromoscillator 10 over line I6 to audio amplifier I5 and the amplified tonesare applied over line 18 to a suitable transducer such as loudspeaker17. At the same time random voltage generator I is activated and startsgenerating a varying voltage such as, for example, a series of rampvoltages. These varying voltages are applied over line 2 to gate 3. Gate3 when opened by a pulse from trigger 12 over line I7 applies amomentary voltage to sample and hold 19 over line 24. Trigger 12 isactivated by pulses from pulser 4 over line 11. Sample and hold 19receives a voltage from gate 3 which depends on the point in the cycleof random generator l at which gate 3 is opened by trigger pulses fromtrigger 112. This received voltage is held until the next sample istaken through gate 3. This held voltage is applied to voltage driver 21over line 23 where a corresponding driver voltage is produced suitablefor controlling voltage controlled oscillator I0 over line 20. Thisvoltage applied from driver 21 causes the frequency or tone ofoscillator I0 to assume a new value which in turn is emitted overloudspeaker I7. Thus, at each pulse from pulser 4, a new tone isproduced and emitted and this new tone is randomly determined by theinstantaneous voltage gate by gate 3 from random voltage generator 1.The rate at which the tones are changed and emitted is determined by thepulse rate of pulser 4 which in turn is detennined by the setting ofpulse rate control 5. The number of pulses of tone emitted or the lengthof time during which they are emitted for each closure of pushbuttonswitch 13 depends on the time constants of monostable switch 22 sincewhen switch 22 opens, the system stops all activity.

In order to operate the device with a steady pitch (but adjustable) aswitch 204, 205, 206 is provided for switching the frequency control ofvoltage controlled oscillator 10 from the random voltage generator to anadjustable voltage source 207.

An interesting and unusual efiect can be provided if the power to pulser4 is supplied through transistor 230 operated as a level detector orpulse counting switch. Pulses from line 7 over line 231 and throughintegrating resistor 232 serve to charge capacitor 233. Power to pulser4 is supplied from line 33 through resistor 234 connected to collector235 and over line 236. When capacitor 233 has been charged to theconduction point of base 237, collector 235 conducts dropping voltagethrough resistor 234 and lowering the voltage over line 236 to pulser 4causing it to stop pulsing. As capacitor 233 discharges, the collectordrops, the voltage rises and pulser 4 starts to generate pulses again.The object is to prevent a monotonous sound being produced from steadyclosure of pushbutton 113.

FIG. 2 is a schematic circuit diagram of a circuit suitable for use inthe system shown in FIG. I and described above. The corresponding FIG. Inumerals are shown in parentheses. The pulser (4) is shown as aunijunction oscillator employing unijunction transistor 25 and having afrequency controlled by variable resistor 26 (5). Pulses are applied tothe keyer, transistor 36 (8) through a pulse shaping network includingresistor 33 and capacitors 34 and 35 and a gain control 37 over lead 33.The voltage controlled oscillator employing unijunction transistor 41(I0) and a frequency control dynamic resistor supplied by transistor 42and controlled by the setting of potentiometer 43 and the voltagesupplied over line 44. The tone or signal from oscillator 4ll-42 isapplied to keyer 36 over lead 40 to emitter 39. The keyed tone isapplied to amplifier 42 (15) and in turn to loudspeaker 43 (17). Therandom generator is a unijunction oscillator employing unijunctiontransistor 45 (I) and having suitable frequency control means such asvariable capacitor 46. The ramp voltages generated by this oscillatorare applied over lead 47 (2) and through emitter follower transistors 48and 49 to gate transistor 50 (3). Gate 50 is closed by a signal overline 54 (17) which in turn is derived from pulser 25 over lead 56 (II)and through trigger transistor 55 (12). When gate 50 is closed theinstantaneous voltage from random generator 45 is ap plied to a sampleand hold device such as capacitor 51 connected to field effecttransistor 52 (19). This voltage sample is applied through a voltagedriver transistor 53 (21) over collector 58 and potentiometer 57 to line44 (20) back to base 59 of the frequency control transistor 42 ofvoltage controlled oscillator 41 Each time pulser 25 generates a pulse anew frequency is thus generated in a randomly determined manner.

The sequence described above is initiated by actuating a monostableswitch comprising transistors 28 and 29 (14) by closing a suitableswitch such as pushbutton 27 (13) and ap plying energizing voltage overlead 30 (22) to the bias ter minals 31 of the pulser, keyer and so onforming the complete circuit as described above.

Details of the operation of the individual circuits pulser, keyer and soon have not been supplied since these are all well-known devicesindividually operating in a conventional manner. The invention residesrather in the novel combination and interconnection of these devices toprovide new, useful and unobvious results.

To review briefly, the operator presses button 27 (13) energizing thesystem and initiating the sequence of operation. Bursts of tone areproduced, each pulse producing a new ran dom pitch until the monostableswitch resets and shuts the system off. The next time the button ispressed another sequence of entirely different tones is produced and soon indefinitely. The average pitch of the tones can be changed byadjusting potentiometer 43, the tonal increments can be changed bycontrols 46 and 57 and the rate of production of tone bursts can bechanged by adjusting variable resistors 26.

FIG. 3 is a modified form of the present invention shown in blockdiagram form. When pushbutton 60 is pressed, a circuit is closed overline 61 actuating trigger circuit 62 which in turn emits a pulse overline 63 to pulse shaper 64. Pulse shaper 64 shapes the received pulseinto the desired shape for keyer purposes and passes it over line 65 tokeyer 68. Keyer 68 further shapes the received pulse and gate line fromtone generator 66 received over line 67 into audio amplifier 70 overline 69 providing desired attack and decay characteristics. Speaker 72receiving the amplified signals over line 71 reproduces the gated andshaped sounds from amplifier 70. The resultant sound may be likened tostriking a bell or gong once with a mallet, hammer or other suitabledevice. The attack can be infinitely varied by variations in thetrigger, pulse shaper and keyer circuits. it can be long or short alsowith infinite variations. The pitch of the sound can be high or low oranything in between. The harmonic spectrum can be shaped as desired inthe audio generator. Volume can be loud or soft as required byadjustment of the gain of the audio amplifier. The analogy withconventional bells will be evident since the mallet is represented bythe shaped pulse from the trigger and the gong or bell is replaced bythe audio or tone generator, audio amplifier and speaker. Feedback overline 73, through feedback device 74 and over line 75 to the triggercircuit provides means for disabling the trigger, so that the pushbuttonis inoperative until the signal on line 71 has decayed to a chosen pointin order to achieve a one stroke effect.

FIG. 4 is another form of the present invention shown in block diagramform. This is a two-bell form in which pushbutton 76 closes a circuitover line 77 to activate multivibrator 78. Multivibrator 78 alternatelysends pulses over lines 79 and 80 to pulse shapers 81 and 82. Thesepulse shapers in turn send pulses over lines 83 and 84 to keyers 85 and86 which gate signals from audio generators 87 and 89 over lines 88 and90 with the desired attack and decay characteristics for each. The gatedsignals are fed over lines 91 and 92 to combine in audio amplifier 93.The amplified bell-tone signals are fed over line 94 to speaker 95 foraudible reproduction. This system is analogous to two bells with asingle clapper. The bell tones are determined by the frequencies towhich the audio generators 87 and 89 are adjusted. The attack and decaycharacteristics are determined by the pulse shapers and keyercharacteristics. The rate of striking is determined by the period ofmultivibrator 78.

FIG. 5 is still another form of the present invention shown in blockdiagram form. This form provides for sequential operation of a simulatedseries of bell like or other audible signaling sounds, each tone orsound being held and/or decayed individually and by independentlyadjustable hold and decay means. Thus, pitch, tonal spectrum, attack anddecay are individually adjustable. Pressing pushbutton 96 closes acircuit over line 98 turning on trigger 97 sending a pulse over line 99to flip-flop 100. Flip-flop 100 sends a pulse out over line 113 to pulseshaper 120 which passes a shaped pulse to keyer 138 over line 137 whereit is processed even further and passes tone signals from audiogenerator 139 over line 140 to provide tone signals with chosen attackand decay characteristics over line 143 to audio amplifier 126 and fromthere over line 127 to speaker 128.

Output pulses from flip-flop 100 are also applied over line 101 to delaydevice 102, which may be any suitable time delay device, such as aunijunction transistor ramp generator, the output of which is appliedover line 103 to the second flip-flop 104 causing it to generate apulse. The output pulse from this second flip-flop 104 is similarlyconveyed over line 114 to a second pulse shaper 119, and from there overline 133 to keyer 134 controlling tones from audio generator 135 overline 136 to audio amplifier 126 over line 142. The characteristics ofthis second tone burst is determined in pitch by audio generator 135 andin timing by delay device 102 and in attack and decay characteristics bypulse shaper 119 and keyer 134.

Similarly, any desired number of additionally delayed pitch and shapedetermined tone bursts or bell-like tones can be provided. Twoadditional are provided as shown in FIG. 5, one after delay in delaydevice 106 over lines and 107, flipflop 108 over line 115, pulse shaper118 over line 129 to keyer 130, controlling tones from audio generator131 over lines 132 and 141 to audio amplifier 126 and speaker 128; andanother after further delay in delay device 110 over lines 109 and 111to flip-flop 112 and over line 116 to pulse shaper 117, line 121 tokeyer 122 controlling tones from audio generator 123 over lines 124 and125 to amplifier 126 and speaker 128. Feedback over line from audioamplifier output line 127 (or the last flip-flop in the chain 112) maybe used to prevent retriggering trigger 97 until the sequence has beencompleted. An additional feedback over line 146 can be used to produce aring counter effect in which the sequence is automatically repeated.

FIG. 6 shows in block diagram form a modified means for providing theswitching sequence used in the multiple tone device of FlG. 5. Only theportion of the system is shown for generating the sequence of pulses tobe applied to the keyers, either directly or through pulse shapers. lnthis modification monostable trigger 147 is activated by switch(pushbutton) 148 and over line 149 turns on pulser 150. The output ofpulser 150 is applied to line 151 and distributed to a shift registercomprising flip-flops 152, 156, and 164 over lines 151,153, 157 and 161.interconnections 155, 159 and 163 are provided so that the flip-flopswill trigger in sequence producing pulses successively over lines 154,158, 162 and 165 to potentiometers 208, 219, 221 and 224 respectively.Predetermined portions of the output pulses appearing across thesepotentiometers are selected by adjustable arms 218, 220, 223, and 225and in turn applied through isolating diodes 209, 217, 222 and 226 andline 229 to voltage controlled oscillator 210. Thus, predetermined butadjustable tones in a repeated pattern are produced and applied overline 211 to keyer 212. Keyer 212 is keyed from pulser 150 over commonline 151 and feeds the sequence of tones in sequence over line 213 toamplifier 214 and in turn over line 215 to speaker 216.

FlG. 7 is a further modification of the pulse sequence generator inwhich the monostable 166 actuated by pushbutton 167 energizes a steppingswitch 169 over line 168 and provides a sequence of switch closuresbetween movable common contact 170 and a sequence of fixed contacts 171,173, 175 and "7 providing circuits to a series of keyers (or interposedpulse shapers) over leads 172, 174, 176 and 178 respectively.

FIG. 8 is a still further modification with monostable 179 actuated byswitch 180 and starting a suitable means for driving contact drum 184such as motor 182 connected over line 181 and driving drum shaft 183.Drum 184 carries a series of contacts 185; I87, 189 and 191 providingsequenced circuit closure to keyer lines 186, 188, 190 and 192respectively.

FIG. 9 is still another modification in which a series of contacts 196,199, 200 and 202 are carried by drum 193 and providing a sequence ofkeyer circuit closures over lines 197, 198, 201 and 203 respectivelyDrum 193 may be turned to provide the keyer circuit closure sequence byhand as by means of a hand key 194 connected to drum 193 by shaft 195.

While the forms of the invention shown in FIG. 5 through 9 provide asequence of four any desired number may be used, four having been chosenmerely for purposes of illustration. A number of ways have been shownfor generating the sequence of pulses but many other ways will beapparent to those skilled in the art and in keeping with the spirit andscope of the inventron.

While various forms of the present invention have been shown anddescribed, many modifications will be apparent to those skilled in theart and within the spirit and scope of the invention as set forth, inparticular, in the appended claims.

lclaim;

l. in a signalling device the combination of:

a plurality of tone generators;

an audio amplifier;

a speaker coupled to said audio amplifier;

a plurality of keyers for applying tones from said tone generators tosaid amplifier;

a switch operated pulse generator for generating a series of pulses toactuate said keyers;

and time delay means coupled between said pulse generator and saidkeyers for supplying actuating signals to said keyers in sequence atpredetermined intervals of time.

2. A signalling device as set forth in claim 1;

wherein said time delay means is adapted to provide different timeintervals between said keyer actuating signals.

3. A signalling device as set forth in claim 1;

wherein said time delay means include unijunction transistor oscillatormeans.

4. A signalling device as set forth in claim 1;

wherein said time delay means includes a shift register for providing aplurality of timed output pulses to said keyers.

5. A signalling device as set forth in claim 1;

and means for modifying said pulse generating means in response tocontinued closure of said switch.

6. A signalling device as set forth in claim 1 and including;

a low frequency random voltage generator coupled to said tone generatorsfor controlling the frequencies of said tone generators.

1. In a signalling device the combination of: a plurality of tonegenerators; an audio amplifier; a speaker coupled to said audioamplifier; a plurality of keyers for applying tones from said tonegenerators to said amplifier; a switch operated pulse generator forgenerating a series of pulses to actuate said keyers; and time delaymeans coupled between said pulse generator and said keyers for supplyingactuating signals to said keyers in sequence at predetermined intervalsof time.
 2. A signalling device as set forth in claim 1; wherein saidtime delay means is adapted to provide different time intervals betweensaid keyer actuating signals.
 3. A signalling device as set forth inclaim 1; wherein said time delay means include unijunction transistoroscillator means.
 4. A signalling device as set forth in claim 1;wherein said time delay means includes a shift register for providing aplurality of timEd output pulses to said keyers.
 5. A signalling deviceas set forth in claim 1; and means for modifying said pulse generatingmeans in response to continued closure of said switch.
 6. A signallingdevice as set forth in claim 1 and including; a low frequency randomvoltage generator coupled to said tone generators for controlling thefrequencies of said tone generators.